The goal of the projct is to exploit newly developed systems for hemodialysis culture (HDC) as a way to simulate in vivo conditions for growth in mammalian blood, without phagocytosis or immune reactions. In the proposed continuation work, a prosthetic HDC unit will be used and an attempt will be made to culture susceptible mammalian cells in association with virulent Treponema pallidum and Neisseria gonorrhoeae. Host-parasite interactions in HDC also will be examined with other parasitic agents of infectious disease. Bibliographic references: Quarles, J.M., R.C. Belding, T.C. Beaman, and P. Gerhardt. 1974. Hemodialysis culture of Serratia marcescens in a goat - artificial kidney - fermentor system. Infec. Immun. 9:550-558. Frederick, J.J., T.R. Corner, and P. Gerhardt. 1974. Antimicrobial actions of hexachlorophene: Inhibition of respiration in Bacillus megaterium. Antimicrob. Agents Chemother. 6:712-721.